Well treatment apparatus



June 3, 1952 J. D. HAYNl-:s

WELL TREATMENT APPARATUS 4 Sheets-Sheet 1 Filed July l5, 1946 IIIIIIlllIllllllilliIlllllllllllllllllllll.

----VsfsrL 195 Fig@ INVENTOR. J0me5 D. Haynes June 3, 1952 J. D. HAYNl-:s

vWEILJ.- TREATMENT APPARATUS 4 Sheets-Sheet 2 Filed July l5. 1946 fig 8 INVENTOR. James D. Haynes BY ATTORNEYS June 3, 1952 J. D. HAYNEs WELL. TREATMENT APPARATUS 4 Sheets-Sheet 3 Filed July l5, 1946 illllhl'l-IIIIKII l INVENTOR. Jmes. Haynes mam/MAM ATTORNEYS June 3, l952 J. DLHAYNEs WELL TREATMENT APPARATUS 4 Sheets-Sheet 4 Filed July 15, 1946 .lllllilllllllllltillin!!n INVENTOR. James 0. Haynes ATTORNEYS Patented June 3,

WELL TREATMENT APPARATUS .llames D. Haynes, Kilgore, Tex., assignor to The Dow Chemical Company, Midland, Mich., a

corporation of Delaware Application July 15, 1946, Serial No. 683,628

17 Claims. 1

The invention relates to means for treating wells with a fluid agent. It more particularly concerns means for delivering a liquid or fluid material to a selected elevation or zone in a deep well through a tubing string.

In the construction and operation of deep wells, it is oftentimes desirable or necessary to deliver a charge of fluid material of one kind or another to a specific elevation in a well bore and to displace it therefrom into the adjacent formation, as for example, when the producing formation is to be treated with an acid solution or when a water-bearing formation adjacent to an oil-bearing formation is to be sealed with a cementing fluid. The operation of injecting a liquid or fluid into a formation at a specific elevation in a well bore is generally referred to as spotting. Spotting of liquid or fluid materials is usually attempted through the tubing and the liquid or iiuid involved may be delivered from the tubing into either the uncased or cased well bore. in the latter case usually opposite perforations in the casing, and displaced from the well through the perforated casing or uncased well wall into the adjacent formation with a displacing liquid.

Several disadvantages inure to such ypractice among which are that there is no satisfactory way of determining just when the fluid material begins to emerge from the tubing and when the delivery is complete. Without this knowledge, accurate control of the level or elevation in the well of the delivered liquid is difficult, if not impossible, to achieve. A part of the difficulty arises from the nature of the tubing in that its volume is not .precisely predictable under the conditions of use due to variations in its distention under pressure, variations in the amount of space at the tubing collars or joints, and various dimensional inaccuracies in the tubing itself. In addition, the volume of fluid retained, if any, in the tubing is not predictable. Similar difficulties arise on attempting to displace the delivered fluid from the well hole either into space be hindthe casing, if one be present, or into the adjacent formation by means Vof a displacing liquid, because no method is available for ensuring the delivery of the proper volume of displacing fluid at the rightl elevation. Another factor militating against accurate spotting is occasioned by the mixing which inevitably occurs at the interface between the fluid to be spotted and any liquid which proceeds or follows it through the tubing for displacing purposes.

When lthevolumecf fluid to be delivered is rel--y atively small, many of these difficulties are accentuated. For example, in the application of resin-forming liquids to sealing, plugging, and other operations in well bores, as described in U. S. Patent No. 2,274,297, cases arise in which it is highly desirable to deliver a small Ibut precisely known amount of resin-forming liquid at a specific elevation in a well zbore, as in sealing a zone of water infiltration adjacent to an oil zone without sealing the latter and forming a seal behind the casing through perforations as in cement squeezing operations. In carrying out such operations, the success of the work is largely determined by the accuracy with which a precisely known volume of cementing fluid can be spotted in the well.

The principal object of the invention is to provide an improved means for spotting a fluid in a well and accurately displacing it into adjacent areas. A particular object is to provide' an improved means for accurately spotting a. relatively small volume of a resin-forming liquid which functions as a binding or cementing agent in a well and signalling the completion of the spotting and displacement into an adjacent area. Other objects and advantages will appear from the following description taken in conjunction with the accompanying drawing in which:

Fig. 1 is a side elevation largely in section of a well equipped with spotting apparatus' constructed in accordance with the principles of the invention for use with two tubing plugs, the apparatus including a tubing string anda plug catcher for catching the tubing plugs and signalling completion of delivery and displacement of fluid. l

Fig. 2 is a cross section on the line 2-2 -of Fig. 1.

Fig. 3 is a cross section on the line 3-3' of Fig. 1.

Fig. 6 is a similar View to Fig. 5 showing the position of the apparatus and plugs in the final stage of the operation. 1

Fig. 7 is a side elevation largely in section of a lower portion of the well of Fig. 1 showing apparatus modied for use with three tubingV plugs which are in a position of the first stage of the spotting operation.

Fig. 8 is a similar view to Fig. 'l showing the position of the plugs and apparatus in a later stage of the operation.

Fig. 9 is a similar view to Fig. 8 showing the position of the plugs and apparatus in a still later stage of the operation.

Fig. 1,0 is the cross section taken on line llla-la' and also the line Ib--lb' of Fig, 7.

Fig. 11 is the cross section on the line Il--l I of Fig. 7.

Fig. 12 is the cross section on the line |2-l2" of Fig. '1.

Fig. 13 is a side elevation of a cased portion of the well of Fig. 1 and shows'the apparatus. oil Fig. "I modied for use with four tubing plugs, the position of the plugs and apparatus being in a rst stage of the operation of spotting a fluid adjacent to a perforated portion of the casing.

Fig. 14 is a similar view to Fig. 13 and shows the position of the plugs and apparatus in the next stage of the operation.

Fig. l5'isa similar view to Fig.' 14 and shows the'position of the plugs and apparatusin the next stage ofthe operation.

Fig. 16 is a similar view to Fig. 15 and shows theI position of the plugs and` apparatus in the last stage of the operation. l

Fig. 1'1'is a side elevation in cross section of a resilientr compressible tubing plug suitable for use-with the apparatus.

Fig-L18 is a side elevation in cross section ofl a form of Vtubing plug suitable for use with the apparatus of Figs. 13-16, inclusive.

Fig. 19 a side elevation in section showing an alternate form of the plug catcher of Figs. 1-6, inclusive.

Fig. 20 is a side elevation in section showing an alternate 'form ofthe plug catcher of-Figs. 7-12, inclusive.

Fig.V 21 is a side elevation in section showing f an alternate form of the plug catcher of Figs. 13H6, inclusive.

Inf the vseveral gures, like numeralsrefer to likeparts.-

Referring to the drawings in detail, a well is shown having abore l, thevupperportion ofwhich is provided with a casing 2 cemented-V inplace with dementr3. The casing extend'sabove the groundlevel4 and isprovided with a casing head having a valved connection 6- leading to thev interior" 'ofi thecasing and av packing gland 1 through which the tubingstring' 8` extends intothewell.- The upperv end of they tubing stringi carriesthe gate valve 9having'anunobstructed bore therethrough when the valve is open.v The gatevalve is connected by a nipple IG and'T Il toa lock chamber l2. Valve I3`on` T- Il provides a connection to the interior of the tubing string below'the lock chamber. The upper end'of-the lock chamber carries a cross I4 having a valved`v connection l5 and pressure gauge I6 for showing the pressure applied through theflock chamber.y The upper side of the cross carries a short nipple I1 which is closed by a removable capfl'.

In Figs. i, 4, amat, there is snowed-,ached tefthe'- lower end of the tubingstringy 8, by a welded ontothe external side of the cylinder 2l` to form a iiuid passage from port'22 tovport23# outside the cylinder 2|. Near the lower end of the cylinder, just above port 23, is a lower stop member 25 having an axial bore. It is held in place by heavy pins 26 (Fig. 2). An axially bored movable tubing plug stop 21 having an externally beveled upper edge 28 is located opposite port 22 and secured to the inside of cylinder 2| by shear pins 29 (Fig. 3). It also serves as a sleeve valve closing port 22, when in the position shown in Figs. 1, 4, and 5, while permitting iiuid to pass through its axial bore longitudinally. Shear pins 29may be designed to give way when the downward pressure tending to move plug stop 21 exceeds aboutlOGO pounds, although other strengths of shearable pins may be used. A tail pipe 3e is secured to the lower end of the plug catcher bya collar 3l. Stop 25 is longitudinally spaced in thev cylinder so that the upper end of the stop is about 1.5 tubing plug lengths from the lower end of stop 21 (before the pins are sheared).

A modication of the plug catcher 20 isl shown in Figs. 1 to 12v inclusive, and designatedy generally by numeral 32. It is intended for use with.

three tubing plugs. Its construction is similar to the plug catcher of Figs. 1 to 6 except that the axially bored movable tubing plug stop 33, which is held in place by shear pins 34 (Fig. 11), is mounted in the cylinder 35 belowthefupperport 36, a distance equal to about 1.5 tubing plugy stop member 39A is provided in the cylinder 35 and is secured in place with heavy'pins 40 which will not shear underV several thousand pounds of load.v The distance between the lower end of the tubing plugn stop and the uppervend of the lower Astop (before the pins are sheared) is about 1 tubing plug length. The plug catcher 32 is attached to theftubing string 8 byva collar I9. The

upper portion of thev well and apparatus isthe'vv same as that of Fig. 1.

Below the plug catcher32 is a packer'4l (shownA unset in Figs. '7 and 8 and set in Fig. 9) for-sealingl the-annularspace in the Well'at the top of thev tailY pipe 42Ywhile permitting the passage of fluidfrom the plug catcher through the packer tothe tai1 1: ip e.42` attached to the bottom of' the packer.y

Anothermodication of the plugcatcher designated generallyby numeral 43, and arranged for use with'fourtubing-plugs in acased portion of the well is shown in Figs. 13 to 16, inclusive.

Plug catchers32fand 43am-identical in construction except th atl'he distance between the upper port 44andtubing-plugstop 45 in-plu'gfcatcher Sis about 2.5;tubing.l plug lengths. As with plug catcherV 32, a plug catcher 43 is provided-with'a by-pass S3, a lowerport 9 4, and a lower stop 95, and-'thevlowerend or thetubing plug stop 45 is about 174 tubingpluglength above the'upperend-` ofthe lower-stop 95.'

Interposed between the tubingstring and the' plug. catcher-.43is a` bore constrictingfandpball' seating elementY designated generallyY bynumeral 45 (best shown in Figs. 15, 16, and 21'), It come prises a short length of tubing 41\connected-to thetubingstringf byacollar 48 and tothe plug catcher 43 by acollar 49; Secured within the tubing 41 fis a bore constricting element 50j in the form of 1an annular ring having an axial borev 5l` A 1 'Ifheborev 5l 1s madeabout 10 to 40 per-centless-in'diame-` ter than that of the tubing string so that resilient compressible tubing plugs adapted for use with the apparatus may be pumped through it when a s uicient diierential pressure (i. e. 500-1500 pounds per square inch or more) is applied.

Attached to the lower end of the plug catcher 33 is a packer 53 (shown unset in Figs. 13, 14, and and set in Fig. 16) for sealing the annular space in the casing 2. rl'he packer is provided with a through passage for fluid from the plug catcher 43 to the tail pipe 53 attached to the bottom of the packer.

The form of tubing plug shown in Fig. 17 is suitable for use with all the forms of the apparatus, although other similar plugs may be used. It comprisesa cylindrical body 55 having a. length preferably about 2 to 4 times its diameter. The ends 56 are recessed to form the lips 57 which produces a squeegee or wiping action as the plug moves along the bore of the tubing in which it is used. The body is preferably made entirely of a resilient compressible material, such as either natural or synthetic rubber, so as to enable it to contract in diameter and pass through the bore 5| of the bore constricting element 53 under pressure. Neoprene is a satisfactory plug material. The diameter of the plug should be slightly larger than the bore of the tubing string so as to make a sliding sealing fit with the bore wall while being driven by fluid pressure through the bore of the tubing.

The tubing plug of Fig. 18 is for use particularly with the apparatus of Figs. 13-16 and its alternate form, Fig. 21. Its cylindrical body portion 38, recessed ends 59, and lips 00 are similar to the corresponding parts of the tubing plug of Fig. 17 and is made of similar material. To one end of the plug is secured the closure ball 6| by screw means 62, the ball being adapted to seat upon the upper beveled edge 52 of the annular ring 50 to form a closure for bore 5|.

The two plug catcher shown in Fig. 19, designated generally by A, is an alternate form of the two plug catcher 20 and assembled in the same way with the tubing string 8 and tail pipe as the two plug catcher 20. The two plug catcher 20A comprises the cylinder |08 having a lateral port |09 near the upper end, the bore of the cylinder being the same as that of the tubing string. The lateral port |09 is closed by the movable tubing plug stop when in the position shown and also functions as a sleeve valve. The tubing plug stop is held in place by shear pins ||l which may be designed to give way under a downward thrust of about 1000 pounds, although other strengths of pins may be used which are capable of being sheared. The upper edge of the tubing plug stop is provided with an external bevel l2 for engaging the end lip of a tubing plug (e. g. Fig. 17 The lower end of the cylinder |00 is provided with an internal thread H3 into which the externally threaded axially bored stop means H4 is screwed. The length of the cylinder-|08 is such that the distance between the bottom of the tubing plug stop I0 and the top of the stop means ||4 is about 1.5 tubing plug lengths (before the pins are sheared).

The upper end of the cylinder |08 is externally threaded and the thread engages the internal thread of the collar H5. Collar H5 is provided with an externally threaded boss 0, the thread of which engages the internal thread on the upper end of the outer tube or cylinder Il, thereby closing the annular space ||8 between the two cylinders at their upper ends. The outer cy1inder has suiiicient length to extend downwardly below the lower end of the cylinder |08. The lower end of tube is internally threaded to receive the reducing coupling ||9 by means of which the tail pipe 30 is secured to the plug catcher assembly 20A. The plug catcher assembly20A is secured to the lower end of the tubing string 3 in place of plug catcher 20 lby the collar |15.

The plug catcher shown in Fig. 20, designated generally by numeral 32A, is an alternate form of the plug catcher 32 and assembled with the tubing string 8, packer 4|, and tail pipe 42 in the same manner as the plug catcher 32. The plug catcher of Fig. 20 comprises the cylinder |2| having a lateral port |22 near the upper end, the bore of the cylinder being the same as that of the tubing string. Below the lateral port, a tubing plug stop |23 held in place by shear pins |24 designed to give way when the downward pressure on the plug stop reaches about 1000 pounds, although other strengths of shear pins may be used. The upper edge of the plug stop |23 is provided with an external bevel |25 adapted to engage the en lip of a tubing plug. f

The distance between the upper end of the plug stop |23 and the lateral port |22 (before the pins are sheared) is about 1.5 tubing plug lengths. The lower end of the cylinder |2| is provided with an internal thread |26 into which is screwed the externally threaded stop means |27, the distance between the upper end of the stop means |21 and the lower end of the tubing plug stop |23 being about 1 tubing plug length. The upper end of the cylinder |2| is externally threaded and the thread engages the internal thread of the collar |28. Collar |23 is provided with an externally threaded boss |29, the external thread of which engages the internal thread on the upper end of the outer tube |30. The boss |29 thus closes the annular space |3| at the top of the Vinner and outer tubes. The outer tube |30 has suillcient length to extend downwardly below the lower end of the cylinder |2I. The lower end of the tube |30 is internally threaded to receive the reducing coupling |32 by means of which the packer 4| is secured to the plug catcher assembly 32A together with the tail pipe 42 to which there is a continuous passage for fluid from the plug catcher through the packer. The plug catcher assembly 32A is secured to the lower end of thc tubing string 3 in place of plug catcher 32 b collar |20. f

The alternate form of plug catcher shown in Fig. 21, designated generally by numeral 43A, is assembled with the tubing string 8, packer 53 and tail pipe 54 in the same manner as the plug catcher 43. This alternate form of plug catcher is similar to that of Fig. 20 differing only in the lengths of its tubular elements. `As shown, plug catcher 43A comprises the inner cylinder |33 hav ing a lateral port |34 near the upper end, the bore of the cylinder being the same as that of the tubing string. Below the lateral port |34 isv a tubing plug stop |35 held in place by shear pins |30 designed similarly to those of the other gures. The upper edge of the plug stop is provided with an external bevel |37 adapted to engage the end lip of a tubing plug.

The distance between the upper end of the plug stop |35 (before the pinsI |30 are sheared) and the lateral port |34 is about 2.5 tubing plug lengths. The lower end of the cylinder |33 is provided with an internal thread |38 into which is screwed the externally threaded stop means |39,

77 `the .distance `between fthe Supper -'end `of the stop means :|39 .and '.th'ef loweraendbf .the tubing `plug stool-36 (before .thezpins ISG-are sheared) Kbeing about :1 `tubing plug length. The upper Vend of the cylinder I 33 .is `.externally .threaded 'Land the thread engages :thei internal thread :of Vthe :collar |40. .The collar.. |411 yis provided withian externally .threaded boss |41, the .thread'of which engages the internal thread on the upper end offthezouter tube |42 which :hassuiiicientlength to extend below .the lower end :of 'the cylinder |33. '.l'he loweriend ofthe tube .|42 is externally :threaded .to Vreceive the reducing coupling If43riby'n1eans5of which the. packer 53 issecuredito Ithe .plugcatcher assembly 43A,together with the Vtail pipel .to which there is .acontinuous passage for'fluidlfrom the .plug catcher .through a the packer. .The :bore constricting and ball seating element FAB .is :attached .to the upper end of .the plug catcher -assemblyi43Arbyfcollar .I'40 .and f4 .isse'cured to .the `lower end ofthe tubing stringz by thecollar In carrying out aspotting operationiofta yliquid or :duid material, any one of the various embodiments of the apparatus described 'may '.'be used,

thechoice depending upon 'the specicneeds of Lthe case. 'I'he'following is.cited as-.illustrative'of apreierred mode of operationin spotting Sa. liquid in'a formation adjacent to anzuncase'd portion'of .a Well hole using the 4apparatus illustrated sin Figs. v1 to 6, wherein .the .formation T63, between formations 64 and 85,.is.toibetreated'witha fluid sealing agent. The alternate form of apparatus which. isshownin Fig. 19rmay be fused ini'sirnilar manner and suchuse is indicated. in what follows.

In'carr-ying out this operation, the tubing string isiassembled, together'with the plug'catcher 2G (or '20A if used) and tail pipe '35, and lowered intothe well until the lower end .of the tail'pipe is adjacent to the Abottom of the stratum t3. The `tail Apipe is preferably made Aseveral feet longer than the thickness of the formation or section thereof to be treated. Insomelinstances, the tail-pipe may be made 'of aplasticor synthetic resin, so that the pipe can be .parted'byast'rong .pull in the Vevent it becomes cementedin the well hole, the tubing string assembly with the;plug catcher being pulled .away leaving the parted portion of the tailpipe in the=well hole. The .un-

cased portion of the Well'hole I below the forma- R tion 63'may be filled with'a Vblanket or otherwise temporarily plugged back, as with `drilling mud or other uid material that does not readilyfdrain away into the formation, or with sand, 'to alevel t1 .near the lower level -of vformation 83.

Thereafter, .the well may Vbe filled with a liquid, such as water or oil, which does not v.interfere with the action lof .the 'fluid "to be spotted, :so as to vrender the Well hydrostatically controllable. Some wells cannotbe lled to thetop without drainage into thief sands 'and in such `cases filling need be carried out-only ltoa `level `that can be attained without undue drainage. As 'illustrated in Fig. l, the -well is shown -lled to the top of the casing with a llingliquid 68, although `the spotting operation canbe .accomplished in similar manner Withoutfllling-the well completely. In placing filling liquid in -the well, the filling liquid may be introduced into the .tubing through valve I While valve .I3 is closed 'The 'sealing `fluid to be spotted .is then intro- 75 ducedlintoth'e ft'ubin'g .'strln'g' immediatly following "the'illling illquid, in similar manner thereto, -in an 'amount calculated Cto -ll et least the well -bore lbetween strata 84 4and $5, Lthe .plug catcher 2,0 or 20A if used), Candltailjpip'e 3|). 'Valvesf and 1I5fY are then closed.' valve I3 p'ned. cap .I8 vwemoved, and a resilient com-pressible 'tubing'plug such-'as shown in-Figfl'giri'sezfte'dln .theloek chamber slz. "The ca'plisthen repaced, 'valve'- I3` closed, andlvalveb! opened. 1

A displacing fluid, such as'oil'or water, isintrof duced through valve I5 into Lthe tubingbehlnd the-first-plugiin .amount preferably just-'equal to the-volume -of'- the sealingiuid, whereupon v-val'ves .9 and I25rare closed,valvefIS'openedcap I8 1removed, and another-similar Atubing :plug inserted in `the :lock chamber 4Cap I8 iis replaced, valve .t3 closed, Avalve il fopened, and `Va driving liquid, 'such as'- water or oil, is'introd'uce'd' into'thetublng 'through valve `=I.5-so as ftodrive the sealingfluid, plugs, and displacing liquid -down th'e tubing. The introduction of `'driving liiuid is Vcontinued until fan vwabrupt rise 4in pressure Iis obtained Aon the gauge .l 5,.indicating that thel ilrst tubing vplug thas passed the lower end of the-tubing string andilanded ontheupperplugstop in thelpl'ug catcherlZ v(orfon plug 'stop H3 if'JZUA is used). Referring-to Fig. 4, illustrating vthis stage 'of'the operation, there -is shown vthe irst tubing plug `e3 landed o'n the movable plug stop'21,the 'sealing iiuid 70, the displacing iiuid 1I, these'cond tubing plug .12, andthedriving iiuid T3 n'th'elr r'esp'ectiveipositions.

In this stage, thesealingguid lpasses through the'cylinder 2| '(or Y1I|l8 Iif 523A is'used) and tall pipes!) andthe1welllholewherelitlrea'ches alevel .75 .above -formation -65andldi'splaceslfllling liquid upwardly in thelwell, and,-ifriilledtheexcess of llingliqzuid Iescapesfrom valve 6 at-the casing head. VAfter thesealing fluid has passed the lower end of the .tubing string, 4the valve E may be closed .and 'the as'sembly `of Sthe tubing Vstring 8, plug catcher 20 (or-'20A if used) and tail pip'e Araised in .the'well softha't thel-owerend BI;v of 'the .tai1;pipe 30iswell.'abovetlie level 74 of the sealing'iiuid. VWhenthe'tublng assembly is raised as .inFig. 5, vfilling .liquid en'ters vthe `'space v"I 5 fi'n the tail .pipe as 4the sealing`iluid therein drains "and rises in .the wellhole.

'The sealing:.fluid.is then displaced from the well hole :into .the adjacent formation. lThis, ls accomplished :by increasing sufiicientl-y the'pressure'prcduced bythe .pump (not shown) Isupplying the driving Yiuid to valve I5 'Sto --ior'ce the shear pins29 of theplugistoplZ-'l toigive-way (or shear pins I.II oflplugstop I|0 if20`Alis used), .thereby allowing 'plug 68 vand :stop 21 lto -move downwardly in ythe -plug catcher lcylinder '21| vfor incylinder I08Jif 20A1isused). As plug 69lm'ov`es downwardly with plugstop 21 l('or III-Dif .20Alis used), port v22 -(or |09 isL20A isused) -is thereby uncovered allowing the displacing vfluid '1I tO -W 'through the by-pass r24 and vport 23 (or 'through the annular space II8 .if 20A is used) into the tail .pipe '30 Iand thence 4in-to 'Itle `lwell hole. As Athe displacement proceeds, plug `1'2 moves downwardly in the tubing l'string 8 'until all the displacement 'uid .has passed 'from the tubing string into Ythe tail 'pipe "and well lhole and theltravel'of the plugiis arrestedbylanding'upon plug 69, .as shown in Fig. 6, thereby closing port '22 (or in like manner Aclosing .port IOS-if l20A is used) and abruptly increasing the `pressure on the gauge I6 as a result lof 'the sudden stoppage of fluid now. The action 'ci' 'the 'displacement fluid is to force the sealing uicl into the Wall of the well hole. The well may be left closed in at this stage for a time sufficient to permit the sealing fluid to harden, thereby forming a treated sheath 1S of the wall of the well hole.

After the sealing fluid has hardened, the apparatus may be withdrawn from the well and the filling liquid and the temporary plug back material removed in any convenient manner.

The modification of the apparatus of Figs. 7-12, inclusive, (or its alternate form 32A, Fig. 20), provides a means to obtain a pressure signal when the tail pipe and passage through the packer have been cleared of fluid by the displacing liquid so that when a packer is used, in confining a cementing fluid below it, retrieving the packer is possible after the operation.

In operating the modification of the apparatus of Figs. 7-12 (or its alternate form 32A as shown in Fig. the assembly of the tubing string 8, plug catcher 32 (or 32A if the alternate form is used), packer 4| and tail pipe 42 is lowered into the well until the lower end 18 of the tail pipe is adjacent to the bottom of the formation 63 to be treated. Similar considerations to those already mentioned in connection with tail pipe 3|) apply to the choice of material for tail pipe 42 and its length. The liquid to be spotted is then introduced into the tubing string 8, the amount employed being determined by the formation 63 Y to be treated. Usually, an amount sufficient to fill the Well hole from the top of the temporary fill 61 to near the top of the formation to be treated is sufcient.

A tubing plug of the type shown in Fig. 17 is then introduced into the tubing string in the man'- ner already described followed by a volume of displacing uid equal to the combined volume of bypass 38 (or the annular space |3| if 32A is used), passage through the packer 4|, and tail pipe 42. A second similar tubing plug is then introduced into the tubing followed by a volume of displacing fluid about equal to that of the fluid to be spotted. This is followed by a third tubing plug and a driving fluid. The introduction of driving fluid is continued and serves as the means to drive the fluid to be spotted from the tubing string into the well while the plugs produce pressure signals indicating when the various fluids have passed the end of the tubing string and reached or passed the plug catcher As the driving fluid is introduced into the tubing string, the plugs and uids therein descend, the rst plug 8B being thereby driven into the plug catcher where it is arrested by stop 33 (or |23 if 32A is used). At this stage, shown in Fig. 7, all the uid to be spotted is displaced from the tubing string through port 36, by-pass 33, port 3l (or through the corresponding ports of 32A if used, viz. port |22, and annular space ISI), the passage through packer 4|, and thence through the tail pipe 42 into the well hole I Where it reaches a level 11 near the top of the formation |53 to be treated; and the tail pipe volume of displacing liquid Bl, second plug 82, uid displacing liquid volume 83, and driving fluid 84 occupy the positions shown in Fig. 7.

Introduction of driving fluid is continued until the pressure gauge I6 shows an abrupt rise in pressure indicating that plug 82 has landed upon plug 8D and closed port 33 (or port |22 if 32A is used). The abrupt pressure rise is the signal that the displacement from the tail pipe of the fluid to be spotted is complete and the introduction of driving fluid is thereupon stopped. The fluid sospotted occupies the well -hole as a fluid column with its upper surface at a level 83, as shown in Fig. S.

The tubing string assembly is then raised so that the lower end '|8 of the tail pipe is above the level 86, as shown in Fig. 9. The packer 4| is then set against the well wall so as to prevent the liquid in the well hole from raising above the packer. After setting the packer, the pressure' is raised upon the driving fluid so as to shear-pins 34 (or pins |24 if 32A is used) and allow the plugs and liquids to descend in the tubing string and plug catcher, thereby causing the upper plug stop 33 (or plug stop |23 if 32A is used) to descend onto the lower stop 33 (or onto stop |21 of 32A and occupies position |23A). At the same time, plug 32 descends uncovering port 36 (or port |22 in 32A if used), thereby allowing the displacing liquid 3| to pass through port 36 into the by-pass 33 and thence through port 31 (or through port H22 and annular space |3| if 32A is used) and packer 4|, and tail pipe 42 into the well. When the transfer of displacing fluid from the tubing to the well hole is completed plug 84 comes to rest on plug 62 and closes port 36 (or port |22 if 32A is used), thereby causing an abrupt increase in the pressure reading on gauge t3, the pressure increase being the signal indicating the completion of the spotting operation. In the completion of the spotting operation, the displacing liquid enters the well hole and displaces the iiuid spotted therein into the wall 81 of the formation 63. Thereafter, pressure is maintained upon the driving uid so as to prevent return l flow until the fluid spotted in the formation has hardened. Afterward, the packer 4l may be unseated and the apparatus removed from the Well. Any residual sealing uid hardened in the-well hole may be drilled out, if necessary, and the temporary lling material removed. I

The modification of the apparatus, shown in Figs. 13-16, inclusive (or the alternate form shown in Fig. 21), provides means for keeping separate each of the several liquids involved in the spot--v ting operation and producing pressure increases for signalling when the various uids have passed the lower end of the tubing so as to indicate the completion of the various stages of the operation. These pressure signals enable the operator to properly manipulate the apparatus to perform an accurate spotting operation.

The operation of the apparatus of Figs, 13-16 is set forth herein as used in spotting a resinforming cementing material through a perforated section of the casing of a well, although this modincation of the apparatus may be used similarly in an uncased portion of a well and for spotting other iiuid materials. In these operations, the alternate form 43A of the plug catcher may be used in similar manner as indicated in what follows. As shown, the bore constricting and ball seating element 43, plug catcher 43 (or 43A if the alternate form is used), retrievable retainer or packer 53, and tail pipe 54 are assembled on the lower end of the tubing string 8 and the assembly is lowered into the well until the end 88 of the tail pipe is adjacent to the bottom of the perforated section 33 of casing 2, the perforations being opposite the formation 33 to be treated. Before lowering the assembly, the portion of the well below the perforated section 89 maybe lled with a temporary filling material to a level 9| just below the perforations 92.

After placing the tubing assembly in the well, the spotting operation may be carried out as follows: A.; nllingf liquid. may. be: introduced, ifi

in amount sufficient to illl the well to a. depth.

sislbstantially. above,the zonegtoV beV treated'.v In manyf; instances, fluid produced.: byv theewell may l'reusedT s by f allowing thev well to. .-produce.. the. re.. quixedamounti: A tubing-plug oftheftype shown 1.7i isfint-roduced .in to the :tubing stringy.' followed: by the. requiredvolume; off cementing materialI (e. g. a liquid plasticaor resin-.forming liquid) for theworkin view,A such .as 'an amount. which willillithecasing to a depth equal to the; .thickness .ofgY formation .90'. A second tubing'v plug, likethe first, isintroduced into the tubing stringvfollowed' by a. displacing liquid, such as' oilonwater; in amount about equal tn thervoluxne. Qt-. they tail pipe: 54A the first; isv introduced into the. tubing string behind-the.displacing-liquid and then asecond quantity: of displacing liquid having; a. volume about-:equal to the: volume. of cementing'material tobedisplacedifrom the-well casing through the perforations. As a fourth or last plug, one ofl the .type shown in 18; is. introducedinto the, tubing string behind the. second displacing liquid, and thislisffollowed by a driving fluid, such asY water, delivered" under suitable pressure through valve |5 as .hy a pumpA (not shownl.

As. thev drivingriluid isiintroduced into the Ytubing'string, thevarious-plugs andV materials laforementioned descend in the .tubing 8'. Whenr the first plug isabout to be driven through thebore constricting and ball seating element 4B, this fact signalled'by `arr increase pressure whichV is on1the=pressure:gaugez.| 8.; Sufficient 'additional; pressure is .then vapplied' to: force.V the: first plug:` through. their bore: element: 5| into; the cyl. inder.- 9B Cor; tl'ieiV cylinder |33; if 43A is used) whereiit. comest toY resta on the; tubing-plug. stopA 45 (or plug stop |35 if-A 43A is used). Assoon; as the plug passesthrough the.zbore.-5| in element 40, there-is: anabrupttdecrease in the pressure onfthef.. driving uid. Similar abrupt increases foliqwedzby. abrupt decreases in pressure are obtadnedfwhen anyof thetubing plugs pass. through thefconstrictingbore 5|. in element 46. Whenthe' rstcplug' comes to rest on the.l plug stop-in theplug catcher, the relative positions of the plugs. and'liquid materials: are as shownV in Fig.- 13, wherein 91 designates thegiirstl plug, 98 the` material to be spotted, 99 the second plug, |00 the-.tail plug; volume of displacing liquid, |0,| the thirdl plug, |02 the casing volume ofr displacing uid, |.03the fourth plug, and |04 the driving liquid. Similar relative positions of the fluids andplugsare held when the alternate form 43A otplugr catcher is used. After the rst` plug 91 has passed below port 44 (or. port |34. if 43A is used). and the introduction of driving fluid |04 isfcontinued, the cementing-material 9.8 passes through port. 414-, bypass93,=v andi thencethrougl'i portf94: (or the material passes throughA port |34 andgthe annular space v|45if 43A is-used), packer 531. andjthe tail pipe 54 intothe casing 2, reachingf alevel |05 (Fig.l 14),. when.. plug 99 enters the plug: catcher andcomesto rest upon plug 91. Just prior tothe entry of plug- 99 into the plug catcher, as. plug 9911s forced through. the.y bore. 51|.;in;9r.1 s,trcting element 4.5,V a pressure. rise, is Obtained n; gauge. I6.; as.` increased. pressure-.is needed". to force the f plug; through' the bore4 conf striction and; this is; followed by an abrupt decrease in pressure as the downwardmovement oftheplugs |0| and |031still in the tubing. string continues;

AtliirdV tubing plug, like GIL,

After plug.` 9.95;comesto;restaupontplug- 9.1, thea tail.y pipe. displacing fluid;v is displaced'. from beneath. plug |0|" through. port' 4.4, byep,ass 93, port' 94;. ('or..` through.; port.' |34. andthe annular. space |45 if 43A=.is.;used), and'thencefthrougha thefpacker 53 :andtftail fpipe 54 :into .the well .hole whereby`v the level*I ofi.' the cementing" material therein israised; to a.h eight;idesignated by;y |06, adjacent to.- the. stop. off the formation. to; bef. treated', and th'e.I tail pipe and appendedpassages are .cleared I of cementing material. Completion. of "this displacement?Y is signalled by abruptlistoppagefofflow: ofdriving fluid as. the third plug |0| entersthe plug. catcher and: comesto rest. upon-plug 99, asshown nFig. 15., and closes port. 4'4 ('or'closesaportn|3.4..if 43A.isfused).:.

The abrupt cessationwofffiow. of" driving, fluid, occasioned bythe closureof'port 41.4V (or port.- |34 if 43A. isused) is.: thesignal that the taillpipef 54 is-cleared r of cementing material, which. then occupies the well casing; and' thatthe: tubing stringassembly is to beraised' untilV the `endV 88' is above-theflevel |06:

After'raising 'the tubing assembly so that the. lower end of the .tailpipe is above the level |06, the retrievable .retainer (packer). 53'is set s o as. to -seal off the; casing,- belowi thepacker, thereby preventing fluid from risingabove the packer and then the pump .supplying .driving fluid; is; oalled upon'to increase the pressure to a point Whichwilllcause the shear pinssupporting theupper plug-stop-45fto shear (or the pins |35. ofiplug stop. |35 1f'43A is-used). After shearing the plug stop pins, the introduction of drivingfffluid' is continued, therebyI causingthe stop 45. (or stop |35 if" 43A. isused-)f to'. descend in theY plug catcher with plugs Sl 'andi'99 untiltheV plug stop comes. to* rest upon stop C(Fig; 16) (or stop |3901. Fig. 21T if. 43A is used). Coincidentallyplug |01 movesy downwardly in the plug catcherr and' uncovers port 44S (or port. |341if '43A1is used).

As soon as port 44. (or port |34 if 43Al is used) is opened' by. forcing plug.- |011 below. the. port 44. (or port |34 if 43`Ais used), the displacing fluid |94. passes .fromthe tubing string througliport 44 (or port- |34), by-pass 93? (or annular spacev |45), and thence` through port: 94. (or annular space |45), the packer 53 andtailpipe 54. into the casing 2 andl displaces the cementing material through perforations 92 into the voids in the formation behind the perforated section of casing. The. displacement is complete when the ball closure: 6| ofthe fourth plug |03 cornes to rest upon the annular ring 59, thereby preventing further downward-travel of driving fluid |04.

as shown .in Fig., 16, and causing an abrupt pressure rise. onA the. gauge. At. this stage, flow of' driving fluidA isstoppedV and pressure is maintained' upon the driving fluidV so as: to prevent return flow of` the cementing material while it is allowed to harden, thereby formingthe ce inenting'deposit` |01 behindv the perforatedsection of the; casingy 89;.

After-the cementing material; has hardened. the pressure; on thedrivi'ng fluid is released.A the packer 53` unseated, and'theftubing assembly removed from the well. Thereafter, the temporary filling 9|V below the perforations may be removed and thecasing cleared, if necessary, of seti cementing material.

Although the invention has'been described particularly for use-in spotting resin-forming liquids o1' plastic-sealing agents in a- Well, I do-not wish tol limit myselfr to the spotting of any particular material as it isfapparent that the apparatus can lbe employed for spotting any material with fluid characteristics, such as that of oil, cement slurries, and the various chemical solutions and iiuid agents used in Well treating, construction, and conditioning. It will be apparent also that the various embodiments of the plug catcher and its alternate forms may be used under some conditions without either a tail pipe or a packer, if desired. In addition, the apparatus of Figs. l-6 (or its alternate form, Fig. 19) may be used with a packer, if desired, by including in the assembly of the plug catcher and tubing string a packer between the lower end of the plug catcher and the upper end of the tail pipe. The preferred assembly includes with the plug catcher a tail pipe connected with the bore of the same so that fluidvwhich passes through the plug catcher by way of either the by-pass or bore of the catcher is delivered to the tail pipe and thence into the well.

It will be apparent, also, that it is not always necessary to raise the assembly of the tubing, plug catcher and tail pipe (with or without a packer) before displacing the agent from the well hole into the adjacent area. For instance when the treating agent used does not have a cementing action (as when an acidizing solution, paraiin solvent, etc. is used) the apparatus may be left in its original position in the well before the final displacing step. Again when the tail pipe is made of a material which is more easily rupturable than ordinary tubing (e. g. when the tail pipe is made of plastic tubing, or the like, as already described), the assembly need not be raised before displacing the agent used from the Well hole even though the agent is a cementing uid as in such cases the tail pipe can be pulled away from any cementing uid which may set around it in the well.

Among the advantages of the invention are ing agent can be introduced into a deep well through a string of tubing and accurately located in the well as to the point of delivery; substantially all the liquid-treating agent introduced into the tubing string reaches the point of delivery; a definite signal is obtained which accurately informs the operator of the completion of the delivery of the iluid material into the well.

Iclaim:

l. A well treating apparatus for spotting a iluid material in a well for use with a string of well tubing and tubing plugs making a sliding sealing nt with the bore of a Well tubing comprising a pair of tubular members arranged concentrically so as -to provide an annular passageway lengthwise of the members; means joining their upper ends together so as to close the said annular passageway at its upper end, the inner one of the tubular members having a lateral port near its upper end communicating with the said annular passageway; a tubing plug stop in the inner tubular member opposite the lateral port so as to form a closure therefor, said tubing plug stop having a longitudinal bore extending therethrough, said longitudinal bore being smaller than that permitting the passage of a tubing plug; shearable means initially holding the said tubing plug in place, said tubing plug stop as in place closing the said lateral port; a stop means mounted in the inner tubular member a distance below the tubing plug stop equal to about 1.5 tubing plug lengths, said stop means having a longitudinal bore extending therethrough for the passage of fluid from above to below the stop 40 that a relatively small volume of a liquid-treatmeans; and coupling means at the upper end of the inner tubular member for connection to the end of a tubing string.

2. A well treating apparatus for spotting a fluid material in a well for use with a string of well tubing and tubing plugs making a sliding sealing nt with the bore of the well tubing comprising a pair of tubular members arranged concentrically so as to provide an annular passageway lengthwise of the members, means joining their upper ends together so as to close the said annular passageway at its upper end, the inner one of the tubular members having a lateral port near its upper end communicating with the said annular passageway; a tubing plug stop in the inner tubular member below the lateral port a distance equal to about 1.5 tubing plug lengths, said tubing plug stop vhaving a longitudinal bore extending therethrough, said longitudinal bore being smaller than that permitting the passage of a tubing plug; shearable means initially holding the said tubing plug stop in place, said tubing stop as in place closing the said lateral port; a stop means mounted in the inner tubular member a distance below the tubing plug stop equal to about 1 tubing plug length, said stop means having a longitudinal bore extending therethrough for the passage of iluid from above to below the stop means; and coupling means at the upper end of the inner tubular member for connection to the end of a tubing string.

3. A well treating apparatus for spotting a iiuid material in a well for use with a string of Well tubing and tubing plugs making a sliding sealing iit with the bore of a well tubing comprising a pair of tubular members arranged' concentrically so as to provide an annular passageway lengthwise of the members; means joining their upper ends together so as to close the said annular passageway at its upper end, the inner one of the tubular members having a, lateral port near its upper end communicating with the said annular passageway; a tubing plug stop in the inner tubular member below the lateral port a distance equal to about 2.5 tubing plug lengths, said tubing plug stop having a longitudinal bore extending therethrough, said longitudinal bore being smaller than that permitting the passage of a tubing plug; shearable means initially holding the said tubing plug stop in place, said tubing plug stop as in place closing the said lateral port; a stop means mounted in the inner tubular member a distance below the tubing plug stop equal to about 1 tubing plug length, said stop means having a longitudinal bore extending therethrough for passage of uid from above'to below the stop means; and coupling means at the upper end of the inner tubular member for connection to the end of a tubing string.

4. A well treating apparatus adapted for use with a string of well tubing and tubing plugs for spotting a uid material in a well comprising the combination of a cylinder having a lateral Y the said upper lateral port; and a lower stop having' a: boreV extending.A therethrough permit-v ting the-.passage of'iluid longitudinally through the cylinder mounted in the cylinder; between the-.upper and lower lateral ports, said lowerstop retainingthesaidtubingfplug stopin the cylinder.

5; A well treating-apparatus adapted for use witlra stringl of well tubing and tubingl plugs for. spotting afviluid material in a well comprising/thecombinatioirofa cylinder having a lateral portxnearitheupper end and another nearl the lowerendfthereo; a passageway for fluid exteriorly of and'secured to the cylinder connecting'the said lateralports; a slidable sleeve valve slide-ble.l withinv the cylinder adaptedv to close the: upper lateral portfwhilepermitting the passageiof fluid-longitudinally through the cylinder; shearable; holdingmeans initially holding said sleevvalve in plaee, said sleeve valve as in place closing-the saidupper lateral port, said sleeve valve@ being adapted to arrest the downward movement of a* tubing: plug in the cylinder; a lower-.stop-having ali-.axial bore extending therethrough mounted in the cylinder between the uppeitand lower lateral ports soV that the distance'between the lower end of the sleeve valve and the upper end of the lower stop is about l.*5- times the length of a tubing plug adapted for use with the apparatus, said lower stop retaining the said tubing plug stop in the cylinder; and means for connecting the upper end of the cylinder to the lower end of a tubing string.

6. A well treating apparatus adapted for use with al string of well tubing and tubing plugs for; spotting a fluid material in a well comprisingjthecombination-of a cylinder having a lateralA port'near the upper end and another near the,1ower;end thereof; a passageway for iiuid exteriorly of and secured to the cylinder connecting the said lateral ports; a tubing plug stop mounted in the cylinder below the upper lateral portsaid tubing plug stop having an axial bore extending therethrough, said axial bore being smallerthan that permitting the passage of a tubing plug; shearable holding means initially holding the tubing plug stop in place; and a lower-stop having an axial bore extending therethrough to permit the passage of fluid longitudinally through the cylinder mounted in the cylinder between the upper and lower lateral ports so that the distance between the upper i end-ofthelower stop and the'lower end of the tubing plug stop is about 1 tubing'plug length, ther lower end of said tubing plug stop being adapted'to-rest upon the-upper end of said lower stop after the'holdingmeans have been sheared y allowing' the'tubing` plug stop to descend in the cylinder:

7. A well treating apparatus adapted for use with a. stringof well tubing and tubing plugs for spottingzaluid material ina well comprising the combination off a cylinder having-a lateral port near: the upper-end and another near the lowerend thereof; a passageway for fluid exteriorlysofand secured'to the cylinder connecting the` said lateral ports; aY tubing plug stop mounted; inthe cylinder below the upper lateral port.4 said tubing plug stop having an axial bore extending therethrough, said axial bore being smaller than that permitting the passage oi a tubing plug; shearable, holding means initially holding. the tubingplugstop in place, the distance-between the upper lateral port andA the top: of the tubing plug stop being equal to about 1.5 times the length of a tubing plug adapted for usawiththe apparatus; a lower stop having t6 anV axial; bore' extending therethrough ,permitting thev passage of uidlongitudinally through the cylinder mounted in the cylinder between thev upper and lowerlateral ports so that the distancebetween the bottom of the tubing plug stop and the top of the lower stop is equal to about the length of a tubing plug, the lower end ofrsaid tubing plug stop being adapted to rest upon the upper end of saidlowcr stop after. the holding means have been sheared allowingthe plug'stop to descend in the cylinder.

8. A well treating apparatus adapted for use with a string of well tubing and tubing plugs for-spotting a uid material in a well comprising the-.combination of a cylinder having a lateral port` near; the upper end and another near the lower end thereof; a passageway for iluidexteriorly of and secured to the cylinder connecting the said lateral ports; a tubing plug stopmounted in the cylinder between the upper and lower lateral ports, said tubing plug stopl having an axial bore extending therethrough, said axial borebeing smaller than that permitting the passage of a tubing plug; shearable holdingy means initially holding the tubing plug stop inplace, the distance between the upper lateral port and the top of the tubing plug stop being about equal to 2.5 times the length of a tubinerr plug adapted for use with the apparatus; a lower stop having an axial bore extending therethrough to permit the passage of iiuid longitudinally through the cylinder mounted in the cylinder between the lower and the upper lateral ports so that the distance between the upper end of the lower stop and the lower end of the tubing plug stop is about 1 tubing plug length, the lower end of said tubing plugl stop being adapted to rest upon the upper end of said lower stop after the holding means have been sheared allowing the tubing plug stop to descend in the cylinder.

9. A well treating apparatus adapted for use with a string of well tubing and tubing plugs for spotting a fluid material in a well comprising the combination of a cylinder having a lateral port near the upper end and another near the lower end thereof; a passageway for uid exteriorly of and secured to the cylinder connecting the said lateral ports; a tubing plug stop in the cylinder near the upper end thereof having an axial bore extending therethrough, said axial bore being smaller than that permitting the passage of a tubing plug; shearable holding means initially holding the tubing plug stop in place; and a lower stop having an axial bore extending therethrough to permit the passage of fluid longitudinally through the cylinder mounted in the cylinder between the upper and lower lateral ports, the lower end of said tubing plug stop being adapted to rest upon the upper end of said lower stopv after the holding means have been sheared allowing the plug stop to descend in the cylinder; means for connecting the upper end of the cylinder to the lowerV end of a tubingV string; and a tail pipe connected to the lower end of the cylinder adapted to conduct fluid passed through the cylinder into the well.

10. A well treating apparatus adapted for use with a string of well tubing and tubing plugs for spottinga fluid material in a well comprising the combination of a cylinder having a lateral port near theupper end and another near the lower end thereof; a passageway for fluid exteriorly of and secured to the cylinder connecting the said lateral ports; a slidable sleeve valve slidably valve being adapted to arrest thedownwardv movement of a tubing plug; a lower stop having an axial bore extending therethrough to permit the passage of fluid longitudinally through the cylinder mounted inthe cylinder between the upper and lower lateral ports so that the distance between the lower end of the Vsleeve valve and the upper end of the lower stop is about 1.5 times the length of a tubing plug adapted for use with the apparatus, said lower stop retaining thesaid sleeve valve in the cylinder; means for connecting the upper end of the cylinder to the lower end of a tubing string; a packer on the lower end of the cylinder adapted to seal the annular space in the well; and a tail pipe on the lower end of the packer adapted to conduct fluid passed through the cylinder into the well.

1l. A well treating apparatus adapted for use with a string of well tubing and tubing plugs for spotting a fluid material in a well comprising the combination of a cylinder having a lateral port near the upper end and another near the lower end thereof; a passageway for fluid exteriorly of and secured to the cylinder connecting the said lateral ports; a tubing plug stop. mounted in;y the cylinder below the upper lateral port, said tubing plug stop having an axial bore extending there'- through, said axial bore being smaller than that permitting the passage of a tubing plug; shearable holding means initially holding the tubing plug stop in place; a lower stop having an axial bore extending therethrough to permit the passage of fluid longitudinally through the cylinder mounted in the cylinder between the upper and lower lateral ports so that the distance between the upper end of the lower stop and the lower end of the tubing plug stop is about 1 tubing plug length, the lower end of said tubing plug stop being adapted to rest upon the upper end of said lower stop after the holding means have been sheared allowing the tubing plug stop to descend in the cylinder; means for connecting the upper end of the cylinder to the lower end of a tubing string; and a tail pipe connected to the lower end of the cylinder adapted to conduct fluid passed through the cylinder into the well.

12. A well treating apparatus adapted for use with a string of well tubing and tubing plugs for spotting a uid material in a well comprising the combination of a cylinder having a lateral port near the upper end and another near the lower end thereof; a passageway for fluid exteriorly of and secured to the cylinder connecting the said lateral ports; a tubing plug stop mounted in the cylinder between the upper and lower lateral ports, said tubing plug stop having an axial bore extending therethrough, said axial bore being smaller than that permitting the passage of a tubing plug; shearable holding means initially holding the tubing plug stop in place, the distance between the upper lateral port and the top of the tubing plug stop being about equal to 1.5 times the length of a tubing plug adapted for use with the apparatus; a lower stop having an axial bore extending therethrough to permit the passage of fluid longitudinally through the cylinder mounted in the cylinder between the upper and the 'lower lateral ports vso that the distance from the bottom of the tubing plug stopv to the top of the lower stop is about 1 tubing plug length, the lower end of said tubing plug stop being adapted to rest upon the upper end of said lower stop` after the holding means have been sheared allowing the plug to descend in the cylinder; means for connecting the upper'end of the cylinder to the lower end of a tubing string; and a tail pipe connected to the lower end of the cylinder adapted to. conduct fluid passed through the cylinder into the well.

13. A well treating apparatus adapted for use with a string of well tubing and tubing plugs for spotting a fluid material in a well comprising the combination of a cylinder havinga lateral port near the upper end and another near the lower end thereof; a passage for uid exteriorly of and secured 'to the cylinder connecting the said lateral ports; a tubing plug sto-p mounted in the cylinder between the upper and lower lateral ports, said tubing plugrstop having an axial bore extending therethrough, said axial bore being smaller than that permitting the passage of a tubing plug; shearable holding means initially holding the tubing plug stop in place, the distance between the upper lateral port and the top of the tubing plug stop being about equal to 2.5 times the length of a tubing plug adapted ,for use with the apparatus; al lower stop having an axial boreextending therethrough to permit the pas. sage of fluid longitudinally through the cylinder mounted in the cylinder between the lower and the upper lateral ports Vso that the distance between the upper end of the lower stop and the lower end of the tubing plug stop is about 1 tubing plug length, the lower end of said tubing plug stop being adapted to rest upon the upper end of said lower stop after the holding means have been sheared allowing the tubing plug stop to descend in the cylinder; means for connecting the upper end of the cylinder to the lower end of a tubing string; and a tail pipe connected to the lower end of the cylinder adapted to conduct fluid passed through the cylinder into the well.

14. A well treating apparatus adapted to be connected to the lower end of a string of well tubing and used with tubing plugs making a sliding sealing fit in the bore of the tubing string for spotting a fluid material in a well comprising a tubular member having a cylindrical bore extending therethrough adapted to receive cylindrical tubing plugs which are adapted to block the passage of uid longitudinally through the tubular member when arrested therein, said tubular member having a lateral port near its upper end; a lower stop member xed in the lower end of the said tubular member, said lower stop member having a longitudinal passage for fluid extending therethrough; an upper stop member releasably secured in the said tubular member a distance above the lower stop member equal to at least one tubing plug length, said upper stop member having a shoulder on its upper end adapted to seat thereon a tubing plug and a longitudinal passage for fluid extending therethrough, said longitudinal passage of said upper stop member being blocked upon the seating of a tubing plug upon the said shoulder, the said lower stop member being adapted to prevent the expulsion of the upper stop member from the lower end of the said tubular member when released; and a fluid passageway means exteriorly of and secured to the tubular member communieating with said lateral port adapted to convey fluid from the said lateral port into the well below the said tubular member.

15. A wellV treating apparatus adauteuto.A be.

connectedw toA theV lower end; of; a string, or vieuI tubing for Spotting ailuidmaterial.:in..a..wellcome prising a cylindricalplug-eatohingrehamber having av longitudinal' bore. extending therethrough adapted'to. receive oylindrioartubingiplugs which are adaptedY to bloekthe passage. of'iiuidlongir tudinaily through the chamber' when. arrelid.

therein,said chamber having a.' lateraiportnear its upperl end; a slidable; Sleeve valveA slidalile` within the chamber adapted; to forni a releaseable. closure for thel said lateral' port, Said4 sleeve. valve havinga shoulder onitsupper end adapted.

to Seat thereona tubingplug, and; Said sleeve' valve having a longitudinal passageway extend?- ing therethrough, said. passageway being Smaller than that permittingtlie pasaagle ofatubingplua.

said longitudinall bere o f said slidable 'sleeve' valveI being blooked'by. a. tubing plug Seating uponjsaidi Shoulder; mea-ns releaseably holding the4 saisi: sleeve vals/ein. the position closingl Said.` port; Said. means releasing its. holden the sleevevalveuuon.

the application of a sufficient predetermined neotable to. atubular String. through which a nexible plug;I be nulriped,7 including a tube atauhedtq'aidltllblll'stlil f0.1', TeCeVng Said plug..a.t.ubula1el1ambel larger. than said plug secured; to.. saisiztube-,sald tube Projecting into saidjchamber inspacedrelationto the inner wall of saidw chamber, said, tubeV having ay passage through its wallopening into said chamber, and as eat'in, saidj tube adapted: forl engagement by tbe-plug- 1f?J Aj. device of, the character described connetablel to. a. tubular string throughy which a flegibleplug: may, be pumped.'4 including a tube attached tasaid tubular stringfor receiving said plug,l a iziibulzni` chamber. larger than said plug secured' to.. said' t 11b e s aid. tubel projecting into saidchamber, spaced relatiogzrtoI the inner wall of. said; chaxnher.,v Saidv tube having a passage throughits wall. opening. into said chamber.

JAMES D. HAYNES.

REFERENCES CITED 'lhefollcwingL references arev of record. in the 111e. off this.Y patent-2 Iilltu'llll?`v STATES PATENTS 

